The difference between .999... and 1 is an infinite number of zeros followed by a 1. However, there's no such thing as an infinite number of zeros followed by a 1, because then it wouldn't be an infinite number of zeros. So the difference between .999r and 1 does not exist, and if there is no difference between two numbers, then those two numbers are the same number. If you think .9r =/= 1 then you're wrong and that's that. But who would ever expect the majority of offtopic to get a math problem correct